This invention relates to a functional polymer comprising active and stable functional groups, and to a method of preparing the same. More particularly, the present invention relates to a functional polymer that comprises repeat units of the form xe2x80x94CH[Ph-CH2CH2xe2x80x94X]xe2x80x94CH2xe2x80x94, where X is a functional group linked through carbon, and to a method of its preparation.
Functional polymers are widely used in industry as separation media and as solid-phase reagents, catalysts and protecting groups for analytical or preparative chemical applications and processes [D. C. Sherrington and P. Hodge, xe2x80x9cSyntheses and Separations Using Functional Polymersxe2x80x9d, John Wiley and Sons, Toronto, 1988]. A functional polymer generally consists of a polymer matrix, in the form of particles, beads or a porous block [C. Viklund, F. Svek, J. M. J. Frxc3xa9chet and K. Irgum, xe2x80x9cMolded porous materials with high flow characteristics for separation or catalysis: control of porous properties during polymerization in bulk solutionxe2x80x9d, Chem. Mater. y1986 v8 p744-750], that is chemically inert to the conditions of its use, including being insoluble in any solvent it is likely to encounter so that it can be retained in a column or easily recovered from out of a product mixture by filtration or other separation for easy isolation of chemical product and reuse of the functional polymer; and also of functional groups, attached to the polymer matrix, that can bind, transform or otherwise interact with chemical species that are dissolved in a permeating fluid, or that confer other advantageous properties to the functional polymer, such as a higher density for best use in floating bed reactors or for easier and faster separation by precipitation, or better wetting and penetration by a particular solvent. Most often, the polymer matrix is of crosslinked polystyrene, due to the ease of its preparation through suspension or other polymerization of styrene or styrene-like monomer (usually, including divinylbenzene as crosslinking agent), with attendant control of particle size, porosity, swellability, surface area, and other aspects of its architecture affecting eventual use; and its good general mechanical and chemical stabilities, though also with the ability to be controllably decorated with any of a wide variety of functional groups. In ion exchange resins, which are manufactured in large quantities for deionizing water and many other purification processes, these functional groups may consist of sulfonic, carboxylic, phosphinic or phosphonic acids or phosphonic ester acids or their salts, or amines or their salts, or quaternary ammonium or phosphonium hydroxides or other of their salts; recoverable solid resins for general acid catalysis would bear sulfonic or phosphoric strong acid groups; chelating resins that recover toxic or expensive metal ions from wastewater may contain combinations of amino and sulfonate, phosphinate, phosphonate or carboxylate groups, along with hydroxyl, ether, thiol, sulfide, ketone, phosphine, phosphoramidate or other Lewis base groups; certain such functional groups, including those having the form of crown ethers [K. Kimura, in K. Takemoto, K. Inaki and R. M. Ottenbrite xe2x80x9cFunctional Monomers and Polymersxe2x80x9d, Marcel Dekker NY y1987 p349-422], amides [A. Akelah and A. Moet xe2x80x9cFunctionalized Polymers and Their Applicationsxe2x80x9d, Chapman and Hall NY y1990], or 1,3-diketones [H. Yeh, B. E. Eichinger, N. H. Andersen, ACS Polym. Prepr. y1981 v22 p184] may in particular coordinate with metal ions to activate their negative counterions for phase-transfer catalyzed nucleophilic substitution or other reactions, or may hold platinum or other catalytic heavy metal species so that these are conserved and re-used from one reaction to the next, while others such as cyclic amidines like 1,8-diazabicyclo[5.4.0]undec-7-ene (xe2x80x9cDBUxe2x80x9d)[M. Tomoi, Y. Kato and H. Kakiuchi, Makromol. Chem. y1984 v185 p2117-2124] are strong though non-nucleophilic bases for organic reactions or anion exchange; halosilyl, haloalkyl, haloacyl, halophosphinyl, halophosphonyl or halosulfonyl functional groups, or anhydride or azlactone functional groups, can covalently bind to other organic molecules so that parts of these are protected while other parts are being chemically modified, the whole later released, such as in solid-phase synthesis of polypeptides, polysaccharides or polynucleotides, or themselves act as agents for catalysis or molecular recognition, as with proteinic enzymes, antibodies or antigens that have been polymer-bound. Phosphorus-containing functional groups can also improve fire resistance in a functional polymer.
While functional polymers may be prepared by polymerization of monomers that already contain the desired functional groups, more commonly they are made by chemically functionalizing or modifying other existing polymer matricesxe2x80x94most commonly, crosslinked polystyrenexe2x80x94as prepared from common monomers through established polymerization recipes that give well-defined and desirable particle and matrix structures and properties. However, existing such modification methods of preparing functional polymers often suffer from disadvantages of hazardous or expensive ingredients or conditions, that result in products that are intrinsically deficient in activity or stability or both [G. D. Darling and J. M. J. Frxc3xa9chet xe2x80x9cDimethylene spacers in functionalized polystyrenesxe2x80x9d, in J. L. Benham and J. F. Kinstle, Eds. xe2x80x9cChemical Reactions on Polymersxe2x80x9d, ACS Symp. Ser. v364, American Chemical Society, Wash. D.C., y1988 p24-36]. For example, the chloromethylation route to the most common anion-exchange and chelating polystyrene-based resins uses or generates highly carcinogenic species, and results in benzyl-heteroatom bonds that are unstable to many conditions of eventual use or regeneration; bromination/lithiation, another general route to functional polymers, employs expensive and sensitive organometallic reagents and, like sulfonation, results in aryl-heteroatom functional groups that may be unstable in acidic conditions. Functional polymers containing aliphatic spacer groups of at least two carbons between polystyrene phenyl and functional group heteroatom would not show either type of chemical instability, and moreover, the deeper penetration of their dangling functional groups into a fluid phase permeating the polymer matrix often allows better and faster interactions with soluble species therein [A. Deratani, G. D. Darling, D. Horak and J. M. J. Frxc3xa9chet xe2x80x9cHeterocyclic polymers as catalysts in organic synthesis. Effect of macromolecular design and microenvironment on the catalytic activity of polymer-supported (dialkylamino)pyridine catalysts.xe2x80x9d Macromolecules y1987 v20 p767]. Several such spacer-containing functional polymers have been prepared via electrophilic aromatic substitutionxe2x80x94either chloromethylation or bromination/lithiationxe2x80x94of aryl nuclei in crosslinked styrene-divinylbenzene copolymer, albeit through tedious multistep syntheses [Darling and Frxc3xa9chet y1988 ibid].
Instead of on styrenic phenyl, modification reactions can be performed on the vinyl groups of polymeric 1-(vinylphenyl)ethylene repeat units. These vinyl groups may be prepared from formyl, chloromethyl, bromoethyl or 1,2-dibromoethyl functional group precursors [M. J. Farrell, M. Alexis and M. Trecarten, Polymer y1983 v24 p114; Darling and Frxc3xa9chet y1988 ibid; T. Yamamizu, M. Akiyama and K. Takeda, React. Polym. y1985 v3 p1731], or remain from anionic [Y. Nagasaki, H. Ito, T. Tsuruta, Makromol. Chem. y1968 v187 p23] or even free-radical [M. C. Faber, H. J. van den Berg, G. Challa and U. K. Pandit, React. Polym. y1989 v11 p117] copolymerization of monomer mixtures that include divinylbenzene. Radical copolymerization with divinylbenzene is a particularly simple way to form a polymer that contains such vinyls, that moreover have here the advantage of being site-isolated; indeed, Rohm and Haas supplies a commercial product, xe2x80x9cAmberlite(copyright) XAD-4 nonionic polymeric adsorbentxe2x80x9d, which analysis thereof indicates to be undoubtedly made by radical copolymerization of a mixture of divinylbenzene and ethylstyrenexe2x80x94which mixture, containing both meta and para isomers of each, is commercially provided under the name xe2x80x9ctechnical-grade divinylbenzenexe2x80x9d [xe2x80x9cAldrich Catalogxe2x80x9d y1997], and so which resulting polymer may be called xe2x80x9cpoly(divinylbenzene)xe2x80x9dxe2x80x94and which contains 30 mol % of polymeric 1-(vinylphenyl)ethylene repeat units, with the remaining repeat units consisting of polymeric 1-(ethylphenyl)ethylene and crosslinking polymeric bis(ethylene)phenyl repeat units [Faber et al y1989 ibid]. Through electrophilic, nucleophilic, radical, transition-metal catalyzed or other additions to such polymeric 1-(vinylphenyl)ethylene repeat units [W. Obrecht, Y. Seitz and W. Funke, Makromol. Chem. y1976 v177 p2235; Faber et al y1989 ibid; Z. Zhengpu, P. Hodge and P. W. Stratford, React. Polym. y1991 v15 p71; J. P. Gao, F. G. Morin and G. D. Darling, Macromolecules y1993 v26 p1196], or by their radical-induced graft copolymerizations with various monomers [T. Brunelet, M. Bartholin and A. Guyot, Angew. Makromol. Chem. y1982 v106 p79], have been provided a wide variety of functional groups, including of the form Ps-CH2xe2x80x94CH2xe2x80x94X, wherein Ps represents a crosslinked polystyrene matrix connecting through phenyl, and X a functional group connecting through a heteroatom, that features advantageous dimethylene spacer [Gao et al y1993 ibid]. Were X to be a functional group linking through carbon, then any heteroatom in the functional group would be ultimately connected to polystyrene phenyl via at least 3 carbon atoms, leading to still greater chemical stability since elimination reactions here too become less favoured, and also still greater activity and interaction with species in permeating fluid through being extended still further away from the polymer backbone.
Useful functional groups such as crown ethers [K. Kimura et al y1987 ibid] may be incorporated into functional polymers through copolymerization with such functional comonomers as modified acrylate, methacrylate or styrene. As previously mentionned though, modification of an existing optimal polymer matrix is a route often to be preferred for its simplicity, versatility, economy and better product properties. Though functional groups such as crown ethers, amides, amidines, ureas, esters, 1,3-dicarbonyl compounds, carboxylic acids, amines and polyols have been incorporated into functional polymers by other routesxe2x80x94typically through reaction with (chloromethyl)polystyrene and consequent labile benzylic ether or other bondsxe2x80x94and though Cxe2x80x94H bonds in such compounds have been added across alkene functionalities in small molecules (often accompanied by polymerization of the alkene)[C. Walling and E. S. Huyser, Org. React. y1963 v13 p91-149], and the corresponding C. radicals have been used to form polymers with functional end groups [J. K. Rasmussen et al, in C. M. Starks xe2x80x9cPhase-Transfer Catalysisxe2x80x9d, Wash. D.C. y1985 p116-127], and though polymeric 1-(vinylphenyl)ethylene repeat units have been made to undergo radical-induced graft copolymerizations with various monomers [T. Brunelet, M. Bartholin and A. Guyot, Angew. Makromol. Chem. y1982 v106 p79], the prior art does not contain examples of such repeat units being monofunctionalized through anti-Markovnikov addition of carbon-centered radicals on their vinyls, nor of the products of these reactions by this or any other routes.
It is an object of this invention to provide a functional polymer bearing carbon-linked functional groups on dimethylene spacers for separation or reactive processes in chemical manufacture or analysis.
It is another object of this invention to provide a functional polymer that can be prepared using readily-available materials and simple conditions and apparatus.
It is another object of this invention to provide a functional polymer, the architecture of whose polymer matrix (e.g. particle size and shape, porosity, swellability, surface area), and type, arrangement and number of whose functional groups, can be controlled.
It is another object of this invention to provide a functional polymer whose functional groups are stable, active, and accessible to a permeating fluid.
It is another object of this invention to provide a functional polymer bearing functional groups that are ether, polyether, crown ether, cryptand, lariat ether, amide, urea, amidine, ester, amine, carboxylic acid, or combinations thereof, in type, arrangement and number sufficient to confer or contribute towards acidity, basicity, ion exchange, fire-resistance, wettability, chelation, coordination, extraction, separation, sorption, density, permeability, catalysis, selectivity, hydrophilicity, reactivity, separability, suspendability, binding of ions, binding of organic molecules, binding of polypeptides, binding of polysaccharides, binding of polynucleotides, molecular recognition, filterability, convertability to other functional groups, or other desirable qualities, or combinations thereof, in a separation medium, chromatographic medium, purification medium, ion-exchange medium, chelating medium, solid-phase non-nucleophilic base, solid-phase reagent, solid-phase catalyst, solid-phase phase-transfer catalyst, solid-phase protecting agent, support for solid-phase synthesis, chemical intermediate, or other application of a functional polymer, or combinations thereof.
In accordance with the invention there is provided a functional polymer with carbon-linked functional groups on dimethylene spacers, comprising repeat units of the form xe2x80x94CH[Ph-CH2CH2xe2x80x94X]xe2x80x94CH2xe2x80x94, that are products of reaction between polymeric 1-(vinylphenyl)ethylene repeat units and an organic compound Hxe2x80x94X, wherein X is a functional group linked through a carbon atom.
In accordance with another aspect of the invention, there is provided a method of preparing a functional polymer, by reacting polymeric 1-(vinylphenyl)ethylene repeat units with an organic compound Hxe2x80x94X in the presence of free radicals, wherein X is a functional group linked through a carbon atom.
In accordance with a preferred embodiment of the invention, there is provided a functional polymer prepared from Hxe2x80x94X, wherein X is a functional group linked through a carbon atom, said carbon atom also being sp2-hybridized and doubly bonded to an oxygen, or being sp3-hybridized and singly bonded to an oxygen, or being sp3-hybridized and singly bonded to a nitrogen that is also singly bonded to an sp2-hybridized carbon, or being sp3-hybridized and singly bonded to a nitrogen and also to an sp2-hybridized carbon, or being sp3-hybridized and singly bonded to two sp2-hybridized carbons.
In accordance with a preferred embodiment of the invention, there is provided a method of preparing a functional polymer, by reacting polymeric 1-(vinylphenyl)ethylene repeat units with an organic compound Hxe2x80x94X in the presence of free radicals, wherein X is a functional group linked through a carbon atom, said carbon atom in Hxe2x80x94X also being sp2-hybridized and doubly bonded to an oxygen, or being sp3-hybridized and singly bonded to an oxygen, or being sp3-hybridized and singly bonded to a nitrogen that is also singly bonded to an sp2-hybridized carbon, or being sp3-hybridized and singly bonded to a nitrogen and also to an sp2-hybridized carbon, or being sp3-hybridized and singly bonded to two sp2-hybridized carbons.
In accordance with a preferred embodiment of the invention, there is provided a functional polymer comprising repeat units of the form xe2x80x94CH[Ph-CH2CH2xe2x80x94X]xe2x80x94CH2xe2x80x94, wherein X is a carbon-linked functional group, and Hxe2x80x94X comprises an N-alkylamide, N-alkyl urea, crown ether, aza crown ether, polyethylene glycol, N-alkyl amidine, amino acid residue, 1,3-diketone, 1,3-diester, or combinations thereof.
In accordance with a preferred embodiment of the invention, there is provided a functional polymer comprising repeat units of the form xe2x80x94CH[Ph-CH2CH2xe2x80x94X]xe2x80x94CH2xe2x80x94, wherein X is a carbon-linked functional group, and Hxe2x80x94X is N-methyl pyrrolidinone, dimethyl acetamide, tetramethylurea, N,Nxe2x80x2-dimethylpropyleneurea, 1,8-diazabicyclo[5.4.0]undec-7-ene, 2,4-pentanedione, diethylmalonate, 18-crown-6, dicyclohexano-18-crown-6, polyethyleneglycol methyl ether 350 g/mol, 2-chloroethyl ether, 2-hydroxyethyl ether, N-methylmorpholine or N-acetyl leucine.
In accordance with a preferred embodiment of the invention, there is provided a method of preparing a functional polymer, by reacting polymeric 1-(vinylphenyl)ethylene repeat units with an organic compound Hxe2x80x94X in the presence of free radicals, wherein X is a functional group linked through a carbon atom, and Hxe2x80x94X comprises an N-alkylamide, N-alkyl urea, crown ether, aza crown ether, polyethylene glycol, N-alkyl amidine, amino acid residue, 1,3-diketone, 1,3-diester, or combinations thereof.
In accordance with a preferred embodiment of the invention, there is provided a method of preparing a functional polymer, by reacting polymeric 1-(vinylphenyl)ethylene repeat units with an organic compound Hxe2x80x94X in the presence of free radicals, wherein X is a functional group linked through a carbon atom, and Hxe2x80x94X is N-methyl pyrrolidinone, dimethyl acetamide, tetramethylurea, N,Nxe2x80x2-dimethylpropyleneurea, 1,8-diazabicyclo[5.4.0]undec-7-ene, 2,4-pentanedione, diethylmalonate, 18-crown-6, dicyclohexano-18-crown-6, polyethyleneglycol methyl ether 350 g/mol, 2-chloroethyl ether, 2-hydroxyethyl ether, N-methylmorpholine or N-acetyl leucine.
In accordance with a preferred embodiment of the invention there is provided a functional polymer with carbon-linked functional groups on dimethylene spacers that has been prepared from a radical copolymer polymer of monomers comprising divinylbenzene.
In accordance with a preferred embodiment of the invention there is provided a functional polymer with carbon-linked functional groups on dimethylene spacers that has been prepared from a radical copolymer of monomers consisiting of meta-divinylbenzene and para-divinylbenzene and meta-ethylstyrene and para-ethylstyrene.
In accordance with a preferred embodiment of the invention there is provided a functional polymer with carbon-linked functional groups on dimethylene spacers that also comprises other functional groups.
In accordance with a preferred embodiment of the invention there is provided a functional polymer with carbon-linked functional groups on dimethylene spacers, said functional groups comprising ether, polyether, crown ether, cryptand, lariat ether, amide, urea, amidine, ester, amine, carboxylic acid, or combinations thereof, in type, arrangement and number sufficient to confer or contribute towards acidity, basicity, ion exchange, fire-resistance, wettability, chelation, coordination, extraction, separation, sorption, density, permeability, catalysis, selectivity, hydrophilicity, reactivity, separability, suspendability, binding of ions, binding of organic molecules, binding of polypeptides, binding of polysaccharides, binding of polynucleotides, molecular recognition, filterability, convertability to other functional groups, or other desirable qualities, or combinations thereof, in a separation medium, chromatographic medium, purification medium, ion-exchange medium, chelating medium, solid-phase non-nucleophilic base, solid-phase reagent, solid-phase catalyst, solid-phase phase-transfer catalyst, solid-phase protecting agent, support for solid-phase synthesis, chemical intermediate, or other application of a functional polymer, or combinations thereof.